Signal lamp lens



Jan. 17, 1939,

0 w. TRAUTNER 2,144,9.36

SIGNAL LAMP LENS Filed Nov. l5, 1937 2 Sheets-Sheet l WGN TRAUTNER. BY

q' c-f ATTORNEYS.

Jan. 17, 1939. w TRA'UTNER 2,144,096

SIGNAL LAMP LENS Filed Nov. l5, 1937 2 Sheets-Sheet 2 INVENTOR., wAG/vTRAUTNER.

BY Ggf/MARNEY 440 on automobiles.

Patented Jan. 17, 1939 UNITED STATES PATENT OFFICE- SIGNAL LAllIP LENSApplication November 15, 1937, Serial No. 174,572

Claims.

My invention relates to a signalling lens, and more particularly, tosuch a lens as having peculiar advantages when used in conjunction witha signal lamp on automotive vehicles.

5 'Ihis application discloses subject matter shown and claimed in mycompanion application entitled Signal lamp bracket, Serial No. 174,573,filed simultaneously with the present application.

Among the objects of my invention are: To

lo provide a signalling lens or window for a signalling lamp, whereinthe danger of a false indication, due to exterior light, is greatlyreduced; to provide a signal lens wherein a maximum of exterior light isreflected therefrom and a maximum l5 of interior light is transmittedtherethrough; to provide a colored signal lens having a structuredesigned to prevent false signals being caused by outside illumination;to provide a signal lens wherein outside light reflected from the lenswill be substantially colorless, and wherein the light transmittedthrough the lens will be colored; and

to provide a lens or translucent window for a light source which willgreatlyreduce the possibility of a false signal when illuminated withoutside light.

My invention possesses numerous other objects and features of advantage,some of which, together with the foregoing, will be set forth in thefollowing description of specific apparatus embodying and utilizing mynovel method. 1t is 3.) therefore to be understood that my method isapplicable to other apparatus, and that I do not limit myself, in anyway, to the apparatus of the present application, as I may adopt variousother apparatus embodiments, utilizing the method,

3,3 within the scope of the appended claims.

The word lens is used broadly herein as denoting a light transmittingwindow, irrespective of light ray concentration.

Signal lamps are utilized for various purposes The tail lamp may betaken as a typical example, and in such a lamp there is, as a generalrule, a light source in the form of an incandescent bulb operating fromthe battery of the automobile, a lamp housing, and a window 45 acing tothe rear, this window usually comprisnig a red lens of varyingconfigurations, in accordance with the ideas of various manufactan-ers.

lt may also be stated, as a general rule, that 5c such warning lampshave, for a red lens, a lens which is well provided with prismaticreflecting surfaces on the surface adjacent the light source, so thatwhen the lens is illuminated by outside light, such as the sun in theday time or other 55 motor lamps at night time, a colored reflectionwill be seen, giving some measure of protection and a reflected signal,even though the lamp bulb is burned out or otherwise out of order.

Even when stop signals are utilized on automobiles, a somewhat similarlens is used, and 5 many times it is the same lens as used for the taillight. Consequently, the reflection of outside light, which isadvantageous in the case of a continuous signal such as the tail light,will be very obviously a disadvantage in the case of the stop light,because the stop light obviously should only be visible when its ownlight source Within is energized.

Several schemes are used to overcome this difficulty in the case of theintermittently actuated stop lights, and the usual manner by which falseindications are combatted is to use a very high candle power lamp in thestop signal, so that the actual stop signal will be a great dealbrighter than any reflected signal. However, even with 20 large candlepower lamps in stop signals, it is very diilcult, in many cases, toobtain an adequate warning in full sun, and my invention herewithpresented is ideally adapted for signals such as stop lights, in orderto greatly reduce the possibility of obtaining a false signal at anytime, even in full sun or under the full illumination from outsideheadlights.

My invention is still more advantageous in its application to adirectional signal which, up to now, has hardly been satisfactory foruse in daylight. A directional signal differs greatly from a stop light;a stop lamp need give no definite configuration, that is, all that isnecessary is gross illumination through a red or amber filter or lens.On the other hand, a directional signal not only requires adequateillumination, but in addition requires definition, and in order for thedirectional signal to `oe satisfactory, this definition must not only besatisfactory in the day time under the full glare of the sun, but alsomust be substantially unaffected by all other outside light, such as thefull sun in the day time or headlights at night, whereby a falseindication might be given. and my invention has therefore solved the 4"problem of a directional index marker which can be adequately andpredeterminedly illuminated and which will not give a false indicationby light falling upon it from outside sources, such as, for example, thesun in the day time or headlights at night.

Broadly as to method, I utilize multiple surfaces, preferably in acomposite lens, and reflect a large portion of the outside light througha colorless material which will thus give no confusinggfaslseindication. I transmit light throughi the composite lensy to give acolored indication,

and Iso design the various surfaces of the com-l pnsit'e: lens that aminimum of outside lightiican enteritheiinterior of the signal lamp, tobe thereafter transmitted back through the lens toftliee onlooker.,Whereas an adequate interior illumina?.w tiem can. give the desiredsignal.

Ii have thus been able to produce an index-lense ywhich is. operablewith great clarity and definition;z in theday time or at night, underthe fulllglaref ofthe sun'or headlights, but which will noti under.nthefsame conditions, give a reflected indication-r leading to falseconclusions by the onlookers. Therefore, my lens is ideally adaptedforuseiin conjunction with a directional signallinggsyst'emz, and willbe described by me as used in oneesuchl signal system, such as thatshown, describediandi claimed by Clarence B. Howard in his applicatiomfor United States Letters Patent entitled; Verhcle signalling system,Serial No. 13559215M April 9, 1937, although it will be obviousrtoztloseskilled in the art that the lens herein` described. and claimed can beutilized inl other.` signalling systems, either directional ornon-directi'onali1 or in any signal lamp where false indications are tobe minimized, irrespective of* whether,I or not a defined index is to beilluminated-f.. Iiiwill' also be obvious that the advantages of,myfinvenitfon are equally applicable to stationary signalling systems,such as railroad installations; and the like.

Referring to the drawings:`

Fig. 1 is a longitudinal sectional view through a preferred embodimentof my invention, as applied to a vehicle signal lamp showing basalcurvature and lens plane, angle.,

Fig. 2 is a cross sectional View, taken as indicated by the line 2-2'iin Fig. 1.

Fig. 3 is an end View,- of the lamp shown in Fig. 1.

Fig. 4 is a plan View of the lamp mask and index marker.

Fig. 5 is a cross sectional view of mask and index lens, taken asindicated by the line 5-5 in Fig. 4.

Fig, 6 is a longitudinal sectional view of the index lens and mask,taken as indicated by the line 6 6 in Fig. 5.

Fig. 7 is a plan view of the basal surface of the lamp.

Referring directly to the drawings, an incandescent lamp 5 is positionedwithin the lamp house I in a lamp base 6, so that the lamp 5 is in thefocus of a reflector 1. This reflector, of any common automotive lamptype, has an outturned lip 9 fitting a shoulder I0 in the large open endof the lamp house, and the lip is held against the shoulder by aresilient gasket II against which is pressed a mask I2, the mask beingmaintained in place by a cover I4 fixed in position at the top by lug I5and at the bottom by cover screw I6. The mask I2 supports an index lensI'I, and the angle of the mask plane is preferably set at '71 to a lineconstituting a chord of the 23 cylindrical curvature passing through thelongest dimension of the streamline basal surface shape.

Mask I2 is shown in plan in Fig. 4, and it will be seen that the maskedge is provided with four peripheral slots I9, spaced apart, and eachhaving a length of not less than 30 of the peripheral arc, thus allowingthe index lens I2 to be rotated to fit conditions to be described later.

Figs. 5 and 6 show the preferred construction of the index marker. Themask I2 is provided on its inner surface with a lip 20 projectinginwardly, the main body of the mask projecting beyond lip; 20.'A to forma mounting ange 2l. The opposed surfaces of thissmounting flange 2li aresliazped to t the curvature of an outside lens. component 22, which-ispreferablyjsemicircular in section` along its shortest dimensionandpreferably of colorless Iighttransmitting material. By colorless, I donot mean: that .it needi be crystal clean, but I do desire-that itsha-lll at: least be a white or nearly white.; translucent: material, orcrystalline clear, preferably, howevem the latter.

A rearv componentnuy is iproyidedi, wider than the front componentf22,and?? having; angular sides 25 so that lip 20;may.beeforcedithereagainst to cooperate therewith;to,i1ockrtlieeentirestructure together and tothe mask/.1 Llprefer to join the front and rearcomponents; atleast, over the major part thereof, to;` form-i al planarjunction 25, and I prefer thati-thissjunctioni. cemented to removedouble refl'ectionssa'ndl to prevent air bubbles therein, and Falso;prefer to make the center section 26 of thexreancompnnent thicker thanthe edge section:L 'lhearear1 surface of the rear or coloredcomponenttfacing' light source 5 is provided with prismatic: ridges 21,and all surfaces of these ridgesaareeprelierably frosted to reducereflection therefrmm. It; is; preferable thati the rean surface ofi'the, component be@ polishedl.

I alsosprefer to formiboliir front and rear com;n ponents of thislensfinomi modifiable plastics, ori what is popularly known asinbreakable glassy; now vuell'known ini the industry. Under these,-circumstances, lip Mama-y' be readily'applied with.. pressure againstthefv-arious components of thee plastic lens so that; they will be heldfirmlyyin: position, and as Willi readily be seen, whenilip.l 20 is;forced into final position, the entire lens is; rrmly locked in positionin the mask slot.

li also prefer tcn run the prismatic ridges across; then narrowestdimension of the lens in ease. a defined directional index is utilized,such as shown in Fig. 4, where',i one portion of the lens defines anarrow head 30 and another portion denes. an arrow shaft 3E. Otherindexing configurations will of course be immediately apparent. to thoseskilled in the: art, and the cross section shown in Fig. 5, of course,may be changed in dimension so that the lens may be built without;indexing characteristics for use, for example as. a stop light, whereonly a gross light source isv needed and no other indication desired.

Referring directly to Figs. 5 and 6 for the optical operation of thelens, it will be seen that the curved colorless component faces exteriorillumination, whereas the colored rear component faces the interiorlight source. Outside illumination will pass through colorless component22 until the junction of the two components is reached, and inasmuch asI prefer to highly polish surfaces entering into this junction, lightreflection at this point is very high, and all light so reflected willcome back to an onlooker as colorless.

However, in case any outside light should pass through the junction 25to the rear surface 2'I of the rear colored component, a great deal ofthis light will be absorbed and not reflected because of the fact thatthis rear surfaceis frosted, and therefore, any light which is absorbedat this point is not reflected back to the outside onlooker.Furthermore, if outside light should pass through the reflectingjunction 25 and through the frosted surface into the interior of thelamp, this light will be completely broken up and thrown out info theinterior of the lamp housing at random angles,

thus preventing any concentration ofl interior light from the outsidepassing back through the lens to the onlooker to give the falseillumination I avoid.

Under extensive trials it has been found that with the lens of myinvention it is almost impossible to obtain outside light conditionswhich will give a false signal of any recognizable value, and never willa false signal be given of sufficient intensity to confuse the onlooker.However, when the interior light source is illuminated, the strong lightfrom the light bulb passes through the frosted surface, through theprisms 21, through the thick part 2B of the rear component, and thenceonto the outside colorless component 22, giving a strong, brilliantillumination which cannot be mistaken, even in daylight or under theglare of following headlights at night.

I have therefore provided a signal lens which may be utilized either inindexing configuration or not, as desired, which will give a minimumresponse upon application of outside light but a maximum response froman interior light source, thus providing a signal to an onlooker whichwill never be confusing, even under the most severe combinations ofoutside illumination.

I claim:l

1. The method of preventing false color illumination of a colored signallamp window, which comprises overlaying said window with a colorlessmaterial, providing a highly reflective joint between said colorlessmaterial and said window, and roughening the rear surface of saidwindowto reduce reflection of outside light passing through said joint.

2. A composite window for a lamp house having a light s ource thereincomprising adjacent inside and outside bodies of light transmittingmaterial in the path of light from said source, said bodies being insubstantial contact over a planar surface substantially at a right angleto the light beam from said source, the inner surface of said outsidebody being polished and light reflective, and the inner surface of saidinside body being frosted.

3. A composite Window in accordance with claim 2, wherein both of saidbodies are formed from a moldable plastic, and a single opaque maskaround the edges of both of said bodies and interlocking therewith.

4. A composite window in accordance with claim 2, wherein said outsidebody is substantially semi-circular in section along its shortestdimension, and wherein the inner surface of said inside body is formedinto prismatic ridges, said inside body having a thicker cross-sectionthereof adjacent the center of said cross-section than at the edgesthereof to correspond with the increased thickness of the outside bodydue to the semicircular section thereof.

5. A composite window for a lamp house having a light source thereincomprising an inside body of colored light transmitting material, anadjacent outside body of colorless light transmitting material, saidbodies being in the path of light from said source, the inner surface ofsaid colorless outside body being light refiective and the insidesurface of said colored inside body being light diffusive, the saidinside and outside bodies being in substantial contact over a planarsurface substantially at a right angle to the light beam from saidsource.

WAGN TRAU'I'NER.

